The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 23, 1980
Filed:
Apr. 21, 1978
Norio Mizutani, Kawasaki, JP;
Yoshinari Hamanishi, Tokyo, JP;
Nippon Kogaku K.K., Tokyo, JP;
Abstract
A telephoto zoom lens comprises a variable power system and a relay lens system. The variable power system comprises a first group provided with a positive refracting power and capable of focusing by displacement along the optical axis, a second group provided with a negative refracting power and capable of continuously varying focal length by displacement along the optical axis and a third group provided with a positive refracting power and capable of maintaining the focal position constant regardless of the change in the focal length by displacement along the optical axis in cooperation with said second group, said system substantially constituting an afocal system to an infinite object. The relay system includes, in the order from the object side, a front group comprising a positive lens component and a negative lens component which are separated, and a rear group comprising a negative meniscus lens component convex to the image side and a positive lens component which are separated, the rear group being separated from the front group by a large air space.